Hot on the Scent of Information

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Hot on the Scent of Information

They say we're nothing but mammals. Info-seeking mammals.

According to research being conducted at the Xerox Palo Alto Research Center, humans look for information on the Web with the same food-gathering techniques employed by animals. Namely, by following its scent.

"Information scent is made of cues that people use to decide whether a path is interesting," says scientist Dr. Ed Chi. "These cues consist (of) images, hyperlinks and bibliographic citations related to the information needed."

Chi and Peter Pirolli lead a team of computer scientists and cognitive psychologists at Xerox PARC, the famous research center that pioneered the desktop computer, the laser printer, and the graphical user interface. Their "information foraging" theory draws on decades of ecological methods to try to predict food-gathering behavior.

They determined that the mathematical models used to describe animals searching for prey also apply to cyberspace-cruising humans.

"Evolutionarily, the optimization strategies that are innate in each one of us in looking for food in the natural environment occur extremely often in just about everything that we do," said Chi.

And it turns out that a good deal of what people do these days is look for stuff on the Web.

According to Chi's research, people almost always start out with a search engine, then engage in what he calls "hub-and-spoke" surfing: They begin at the center, and they follow a trail based on its information scent.

If the scent is sufficiently strong, the surfer will continue to go on that trail. But if the trail is weak, they go back to the hub. "People repeat this process until they're satisfied," Chi said.

Sometimes surfers will switch strategies. If the scent is too low, they go to a different search engine. On the other hand, if there are too many trails, they will get confused and leave. "For example, some stores list all they have on a single Web page," Chi said. "People are overwhelmed by choices and abandon the site, even if the information they're looking for is right there."

The team is currently developing Bloodhound, a commercial application that would automatically measure site usability. "It would surf like a human will surf, and come back with metrics of how navigable a website is," said Chi.

The lessons drawn from this will directly benefit Web designers. The best way to increase usability is to decrease the amount of cognition necessary to find information: Designers must make the trails so obvious that surfers will follow them almost unconsciously. Lean design and visuals are imperative.

"On the Web, the reason some players are more successful than others is precisely because their website is more usable. Revenue follows usability," Chi said. "Sites like Amazon.com are laid out very well."

This concerns search engines as well, and these devise methods to strengthen information scent.

"The idea makes sense," said Danny Sullivan, editor of Search Engine Watch. "In fact, this is the basis of what the Direct Hit service pioneered to refine search results. They measure which links in search results attract clicks and also determine the time spent on sites. The sites that keep people longer are allowed to rise in the rankings."

Krishna Bharat, senior research scientist at Google, is certainly aware of the importance of good smell.

"We provide strong scent so users don't lose time," he said. "We take the text from the page that is relevant to the query, and include it in the summary."

Bharat also stressed the importance of organizing information in a lean design. "That's why we don't distract our users by showing flashy ads," he said. "Advertisers are coming to the realization that ads must have a scent that the user will likely find useful."

Information-foraging theory is pleasing, because it appeals to common sense. But maybe the Internet is pushing us into a realm where natural analogies are not good anymore.

"Cyberspace is unique because we have search engines," said Bharat. "They have magic properties – you can go anywhere you want. There is nothing like it in the real world."